This invention relates to a multifunction apparatus with a plurality of power sources, and more particularly to a tape recorder with an electronic counter, in which a counter section and a tape recorder section are furnished with power independently of each other from respective batteries.
To date, portable tape recorders provided with a clock which also serves as a tape counter are marketed. In such portable tape recorders, the switching between a clock function and a tape counter function is usually done by changing a clock signal source and a carry timing. When the clock is used as such, the clock signal source used is a crystal oscillator operating at a predetermined frequency, and a 60th scale and duodecimal systems are used; at the time of the use as a tape counter the clock signal source is changed by a Hall element or the like producing pulses according to the rotation of the tape reel, and a decimal system is used. The clock, which also serves as tape counter, comprises a C-MOS LSI and a liquid crystal display unit, and its power consumption is very low. Usually, the service life of the battery used for the counter/clock section is very long, mostly longer than one year. On the other hand, the life of the battery used for a tape recorder section is relatively short; in case of a manganese battery or alkaline battery the life is slightly longer than ten hours when the battery is continuously used and a couple of weeks when the battery is used for one hour per day. Therefore, in case where the counter/clock section is furnished with power from the battery of the tape recorder section, the operation of the counter/clock section can be continued only for several weeks at the most. Also, when the power supply to the clock section is stopped, right time display can no longer be obtained. This means that when the counter/clock section is furnished with power from the battery for the tape recorder section, it is necessary to make correction of the time display in the clock section at an interval of several weeks or a shorter interval. This is very cumbersome.
Due to the above, it has been the practice to supply power to the counter/clock section and tape recorder section from respective batteries which are independent of each other. However, the difference in service life between these two independent batteries is posing a problem as described below.
In case of, for instance, a tape recorder having a memory stop function, the memory stop is effected in the following way. A predetermined numerical data value, for instance "0000" is initially set in the counter section. When the tape is run afterwards until the count data in the counter section goes from "9999" to "0000," a timing signal (i.e., carry-out signal) is delivered from the counter section to the tape recorder section, whereupon the operation mode of the tape recorder section is switched to stop the tape. It will be seen that in this tape recorder, in which the operation mode of the tape recorder section is governed by the counter section, if the counter/clock section becomes inoperative the normal operation of the tape recorder section can no longer be obtained. In other words, if the battery for the counter/clock section is exhausted, the function of the tape recorder section is inhibited even though the battery for the tape recorder section may be new or have much lifetime left. In this case, the tape recorder can not be normally used unless the battery for the counter/clock section is replaced. However, since the battery for the counter/clock section has a long life, the time of its replacement is likely to be forgotten, and in many cases no spare battery is provided.